Genetic Links between Endometriosis and Endometriosis-Associated Ovarian Cancer-A Narrative Review (Endometriosis-Associated Cancer).

Endometriosis is a frequent, estrogen-dependent, chronic disease, characterized by the presence of endometrial glands and stroma outside of the uterine cavity. Although it is not considered a precursor of cancer, endometriosis is associated with ovarian cancer. In this review, we summarized the evidence that clear-cell and endometrioid ovarian carcinomas (endometriosis-associated ovarian carcinoma-EAOC) may arise in endometriosis. The most frequent genomic alterations in these carcinomas are mutations in the AT-rich interaction domain containing protein 1A (ARID1A) gene, a subunit of the SWI/SNF chromatin remodeling complex, and alterations in phosphatidylinositol 3-kinase (PI3K) which frequently coexist. Recent studies have also suggested the simultaneous role of the PTEN tumor-suppressor gene in the early malignant transformation of endometriosis and the contribution of deficient MMR (mismatch repair) protein status in the pathogenesis of EAOC. In addition to activating and inactivating mutations in cancer driver genes, the complex pathogenesis of EAOC involves multiple other mechanisms such as the modulation of cancer driver genes via the transcriptional and post-translational (miRNA) modulation of cancer driver genes and the interplay with the inflammatory tissue microenvironment. This knowledge is being translated into the clinical management of endometriosis and EAOC. This includes the identification of the new biomarkers predictive of the risk of endometriosis and cancer, and it will shape the precision oncology treatment of EAOC.

Vulvar angiomyofibroblastoma is molecularly defined by recurrent MTG1-CYP2E1 fusions.

Angiomyofibroblastoma (AMF), a rare benign vulvovaginal mesenchymal tumour, poses a diagnostic challenge due to histologic and immunohistochemical overlap with other vulvar mesenchymal tumours. Recently, MTG1-CYP2E1 fusion transcripts were reported in 5/5 AMFs; no other genetic alterations have been described to date. Herein, we sought to investigate the frequency of the MTG1-CYP2E1 fusion and the presence of other potential genetic alterations in a cohort of AMFs (n = 7, patient age range: 28-49 years). Tumours demonstrated classic morphologic features including alternating hypo/hypercellular areas, capillary channels surrounded by epithelioid/spindled tumour cells, and variable amounts of mature adipose tissue. reverse transcription-polymerase chain reaction (RT-PCR) for MTG1-CYP2E1 fusion, performed in all seven cases, showed the fusion transcript in five of six cases (one case with technical failure). Two tumours, including the one lacking the fusion, were subjected to targeted next-generation sequencing (104 genes) and a sarcoma fusion assay (28 genes); the fusion negative AMF also underwent RNA sequencing. No additional mutations, copy number alterations, or fusion genes were identified with the assays employed. We conclude that the majority of AMFs harbour recurrent MTG1-CYP2E1 fusion transcripts and identification of this fusion may aid in the diagnosis.

PTCH1-GLI1 Fusion-Positive Ovarian Tumor: Report of a Unique Case With Response to Tyrosine Kinase Inhibitor Pazopanib.

Recurrent GLI1 gene fusions have been recently described in a subset of soft tissue tumors showing a distinct monotonous epithelioid morphology with a rich capillary network and frequent S100 protein expression. Three different fusion partners-ACTB, MALAT1, and PTCH1-have been reported with the PTCH1-GLI1 fusion from 2 patients only, both with head and neck tumors. Herein, we report for the first time a PTCH1-GLI1 fusion in a primary ovarian tumor from a female patient aged 54 years who presented with a 21-cm right ovarian mass and mesenteric metastasis. The tumor was diagnosed as "favor malignant melanoma" based on histologic examination and extensive immunohistochemistry studies. The patient received 4 cycles of pembrolizumab and 2 cycles of trabectedin but developed multiple metastases. A next-generation sequencing-based assay detected a PTCH1-GLI1 fusion, which led to a revised pathologic diagnosis and a change of the patient's management. The patient was switched to the tyrosine kinase inhibitor (TKI) pazopanib to target the sonic hedgehog pathway. Her disease was stable 49 months post TKI therapy. Our case report is the first to show that a tumor with GLI1 oncogenic activation was sensitive to a TKI. The morphologic and immunohistochemistry similarities of our patient's tumor to other recently described tumors harboring GLI1 fusions suggest that these tumors may all belong to the same entity of GLI1 fusion-positive neoplasms and may be treated similarly.

Does Ki-67 Have a Role in the Diagnosis of Placental Molar Disease?

The use of p57 immunohistochemistry (IHC) can distinguish complete mole (CM) from partial mole (PM) and nonmolar abortus (NMA). Molecular genotyping (MG) is the gold standard method for the definitive diagnosis of PM and NMA. However, MG is expensive and not always available. Some data suggest Ki-67 IHC may be helpful in distinguishing NMAs from PMs and could be a substitute for MG. In this study, we examined the utility of p57 and Ki-67 IHC stains in the diagnosis of placental molar disease. The study cohort consisted of 60 cases of products of conception (20 CMs, 20 PMs, and 20 NMAs). All CM cases showed absent (<10%) p57 IHC in chorionic villi. All PM and NMA cases had been subjected to MG and showed diandric triploid or biparental inheritance, respectively. Ki-67 and p57 IHC staining was done on formalin-fixed paraffin-embedded sections from all 60 cases. Both IHC stains were interpreted blinded to the diagnosis. On rereview, we recorded the percentage of cells with nuclear p57 staining in villous cytotrophoblast and stromal cells. Ki-67 proliferative index (%) was determined by manual count of at least 500 villous cytotrophoblastic cells in areas with highest Ki-67 reactivity. Any intensity of nuclear staining was considered positive. The utility of p57 IHC is mainly to exclude or confirm CM. Although there is a significantly higher Ki-67 expression in CMs in comparison to PMs and NMAs, this did not add diagnostic utility. PMs tend to have higher Ki-67 expression than NMAs; however, the difference is not statistically significant. Our data suggest that the use of p57 and Ki-67 IHC cannot reliably distinguish PM from NMAs.